Some
of the problems about marine habitat succession are that it is both long term
and happens out of sight.It is also an
area that is under studied and rarely presented to fishery managers or fishers
for that matter.I planned a small
habitat succession experiment on land in my backyard to illustrate this
point.Two years ago this spring I
purposely stopped mowing (read application of energy) a small section of our
backyard lawn.Many neighbors cut and
mow their lawns on a schedule that rivals any transportation routine and apply
fertilizer (which I do not) so my experiment with the loss of energy soon
became a concern to a neighbor last year who offered to cut down this habitat
experiment twice.But I explained that
my lawn mower was a “miniature hurricane” and that the loss of energy quickly
caused land habitat succession to be very visible (which it was) but the loss
of energy in the marine environment on sub tidal habitats is hard to understand
and see.He seemed puzzled and left
shaking his head.

All
summer long small trees spouted, and weeds grew tall and a couple of times he
would discuss it looking at it as he mow his lawn to a fine level of smoothness
only to see a patch of golden rod and young black locust trees sprout amid wild
plants blooming a few feet away.Again
the offer was made this spring to cut down this “wild tangle” but again I
declined.It’s quite noticeable now, I
agreed but wanted some pictures – “It will be gone by Christmas,” he seemed
okay with that.That was the point
--habitat succession on land was quite noticeable and that in just two years it
was something that people could see.Marine habitat succession of sub tidal areas is hard to see and takes
much longer than land.And when marine
succession occurs it’s mostly plants and shellfish that define the habitat
quality change and you can see them also as catches but succession in marine
habitat types is even more difficult.That it can take decades.In sub
tidal areas important habitat indicators is of the bottom itself, which is even
more difficult to ascertain.Most of the
cove and bay bottoms in Connecticut the last two decades have become softer and
often muck filled. It is often referred to as a negative habitat change from
fishers.The soft eelgrass Sapropel bottoms
are damaging to winter flounder and shellfish in high heat but do seem to
improve blue crabs habitat quality.Additional research is needed for habitat quality of soft Sapropel
bottoms however that would require additional funds.

There
is just not a lot of grant money available for “muck studies” it just doesn’t
cry out for research priorities.Sadly,
although Sapropel formation might be the best indicator we have for climate
change for Long Island Sound and apparently it has been almost completely
overlooked.But marine habitat
succession has profound ramifications for coastal life today especially the
history of it, the temperature and energy conditions related to it, impacts to
navigation, shoreline erosion, estuarine ecology, habitat quality and finally
fisheries abundance.Most recently those
areas do have a responsive research community post Irene and Sandy, but when it
comes to marine habitat succession we largely missed the boat. That ship set
sail in the late 1970s and with it a negative “NAO” as climate pattern that is
also frequently “overlooked” (Megalops report # 1, January 2014).

Bottom
sediment quality is so elusive, because it is difficult to see compared to land
habitat succession.That is what is of
interest now is we had a second Great Heat (1974 to 2008); since 2008 the
temperatures have dropped and energy levels significantly increased for New
England thanks for a negative NAO – the North Atlantic Oscillation.The NAO after being positive for so long turned
sharply negative in 2011.A negative NAO
is associated with increased storm activity and cold polar air sinking for
south into the middle US. (Megalops Special Report #1, March 26, 2013)

At
the beginning of the last century The Great Heat 1880-1920 lobster populations
crashed and blue crabs increased.After
1984 blue crabs started to increase and lobsters crashed again.In 1931 the climate and energy levels
reversed and lead to the cooler and stormier 1950s and 1960s.Could 2011 have been our 1931?It is still early to say that but one of the
indicators could be climate in the 1920s, blue crab populations began to drop,
a series of colder winters was thought to have ruined the blue crab habitat
quality, Megalops sets then came too late for blue crabs to survive
increasingly long winters but the stormy weather improved conditions for kelp
forests and lobsters slowly recovered.The bay scallops who became practically extinct from southern New
England waters in 1920s had reproduction success—improve and “came back” sometimes suddenly to the
amazement and delight of coastal fishers who rejoiced to see an old friend
return, it had been a long time.The NAO
turned sharply negative in 1950 – it was the age of the bay scallop and
quahog.Oysters declined to level not
seen since the 1870s.But something also
occurred: bottoms released sulfides
stored during long hot periods killing fish and blue crabs in winter.Sometimes habitat succession is not liked by
us when it happens and winter “kills” became common in the 1950s (Megalops
Program Report #1, April 17, 2013). Winter kills became common after 1930 in
coastal salt ponds.

Habitat Succession
Turns Violent 1931 to 1950

To
coastal property owners however the 1950s and 1960s there was nothing to rejoice
about, while bay scallop production would rise to historic production highs in
Niantic, many coastal residents there were busy repairing seawalls, and
supported new federal efforts at “flood and erosion control “with local” boards
now forming in many municipalities.The
Northeast Atlantic Oscillation appears to be a natural cycle event and it had
turned sharply negative.It is not a new
climate event-- the “Polar Vortex” has been mentioned recently in some weather
forecasts, but the vortex is a feature of the North Atlantic Oscillation (NAO)
but does not directly cause it.Its
presence has been known for quite awhile.In a book titled “Climate Change,” Harlow Sharpley, Editor (Harvard
University Press), Hurd C. Willett describes the “circumpolar vortex” on page
56 and reviews its presence, but it’s quickly recognized today by its large
horseshoe shape storm track across the middle United States, drought often on
the left side while increased rain or snow on the right – our side of this
horse shoe shape storm track.

“The
Cycle is one of alternate expansion and construction of the circumpolar vortex
with equator ward or pole ward displacement of the prevailing storm
tracks.Periods of expansion of the
circumpolar vortex tend to be cool in middle latitudes, accompanied by
increased rainfall in lower middle latitudes and decreased rainfall in the
highest latitudes.”Periods of
contraction of the circumpolar vortex are marked by warm characteristics
particularly in the higher latitude.”(1953)

First
impacted water bodies then were shallow and often had restricted flushing –
tidal restrictions.As such they had
increased residence periods for nitrogen locked up in organic matter –
compost.As energy levels decreased
(storm intensity/frequently) it built up and then rotted.In the absence of oxygen, bacteria thrived,
consuming organic matter while releasing hydrogen sulfide gas.When that happened, bay bottoms turned
black.Coastal residents a century ago
watched this also happen and they did one of the few things they could do
restore the energy and this was accomplished on a limited scale – coastal
dredging by horse drawn scoops.

The
previous period of warmth 1880-1920 saw bay bottoms turn soft and black.Oyster sets were huge, blue crabs became
abundant.Black mayonnaise more aptly
termed “fresh Sapropel” grew thick creating deep deposits. After 1931,
temperatures dropped and storm intensity increased. The built up Sapropel
deposits were washed from coves and bays and with it the byproduct of high heat
low oxygen reduction by bacteria, sulfides.At times sulfides could and did kill fish especially under thick ice.
These events became known as winter kill.

In
the 1940s, ice returned to New England’s salt ponds; duck hunters who enjoyed
“open” winters before now saw conditions become colder.Thick ice formed on salt ponds, in areas of
tidal flow winter ice scour increased re-suspending these Sapropel deposits and
with it sulfide fish kills, termed black water deaths.(*Black water is rarely used today although
some old aquarium texts still mention it). Sulfide is extremely toxic to fish,
effectively blocking oxygen exchange in the gill tissue itself, it binds so
completely that even in the presence of oxygen, and fish perish quickly.Fish simply cannot access the oxygen and
flee.In the transition years, winter
fish kills on Cape Cod increased along with colder temperatures came a sudden
increase in storm frequency and storm intensity.Coastal coves with shallow narrow connections
to the sea often became blocked with ice and subject to winter sulfide
kills.Coves can also become blocked by
storms and coastal residents a century ago would use oxen and horse teams to
unblock them. They would do this because this habitat succession threatened
valuable herring/alewife runs, seine fisheries and shellfish.

A
fish kill (striped bass) happened a few weeks ago in the Black Hall River in
the Old Lyme; The Black Hall had been one of the areas that had overwintering
blue crabs survive and the past three years one of the first areas to report
blue crab catches.No doubt a thin layer
of Black mayonnaise in oxygen helps blue crabs, but deep layers contain high
amounts of sulfide and can kill blue crabs as well as fish.One of the signals of declining habitat quality
for blue crabs is the reports of such winter kills.(Megalops Program Report #1, April 17, 2013).

The
buildup of Sapropel (black mayonnaise) has happened here before and a few
accounts have survived a local habitat history that describes hard bottom habitat
transitions to soft ones.

One
of these accounts describes Quiambaug Cove in Stonington. Edgar P. Farnell
wrote to me in June 1987 as part of an investigation of increasing Sapropel
(Black Mayonnaise) in Quiambaug Cove, Stonington and comments by eastern CT
winter flounder fishers.I was working
for the University of Connecticut at the time. Winter flounder fishers reported
that heavy muck was now covering once productive winter flounder habitats and
those changes had occurred after 1974 when the Negative NAO turned positive to
warming temperatures in bringing Southern New England.This increasing warm temperatures naturally
lowered oxygen levels and small coves were some of the first impacted water
bodies; they were shallow and often had restricted flushing- tidal
restrictions. As such, they had increased residence periods for nitrogen locked
in organic matter – compost mostly leaves.As energy levels decreased (storm intensity/frequency) and temperature
increased this created natural anoxic conditions. Organic matter accumulated
quickly and then rotted forming Sapropel.In the absence of oxygen bacterial reduction process, sulfate reducing
bacteria thrives, continuing consuming organic matter while releasing hydrogen
sulfide gas.When that happened, bay
bottoms turned black.Coastal residents
a century ago watched this also happen and they did one of the few things they
could do – restore the energy to increase flushing and this was accomplished on
a limited scale, by dredging – salt pond and cove inlets.

The
letter that Mr. Farnell wrote to me encompasses those features of coastal salt
ponds a century ago is included below,

Dear Mr. Visel:

Mr. Frank Rich has advised me that you are
considering improving the tidal flow in Quiambaug Cove.

The buildup of much and heavy vegetation is
more of a concern. It certainly has had an effect on the Cove as a whole
including clams, oysters, crabs, fish and mussels. When the Filter Plant was
built many years ago, the north end of the Cove increased the buildup of heavy
mud that has continued for many years.

When my father (deceased 1972) was young, he
recalled that every spring landowners along the cove would use a team of oxen
and plow to dredge the Cove every year between the bridges at a perigee tide.
This, no doubt, improved the tidal flow, because when I was a boy, the Cove had
little of the muck which now prevails.

I thought my Father’s recollection might be
of help in validating your forecast that dredging the area between the bridges
would have a dramatic effect on the quality of sea life within the Cove.

Very truly yours,

Edgar P. Farnell

(June 30, 1987)

In
cold weather as ice built up frequently cold water sulfide kills happened
naturally and there was nothing coastal land owners could do except wait for
spring.They didn’t like this habitat
succession and sought to correct tidal exchange problems themselves and
therefore the recent public policy dilemma over climate changes – how much is
“us” and how much is “natural.”

Did
a stormy colder period follow a relatively warm period (1880-1920) as coastal
storms then were few as compared to the storm filled 1950s and 1960s?What were the habitat conditions, did they
succeed like terrestrial ones, or could hurricanes in the marine environment be
the equivalent of land forest fires and quicken habitat succession?It is natural to see blue crab populations
and lobster populations reverse in our area subject to changes in temperature
and energy levels, and if so how many times before could such decreases in some
species provide clues for another?

These
are some of the questions that come up with a long term environmental fisheries
history review that places Mother Nature, with equal footing (a legal term
would say standing) as to our involvement?Is it over fishing or a declining habitat quality?Is shoreline erosion something we should just
expect during negative NAOS.This is a
huge issue for the environmental community, coastal landowners, fishers and the
public.This is why the habitat
questions remain, the oyster industry grew to an enormous size during The Great
Heat (1880-1920) during a time of an unprecedented period of coastal
pollution?The Connecticut Lobster
fishery failed after pollution controls amid excellent conservation and
resource management laws.At the turn of
the century (1900), bay scallops collapsed in southern New England but in 1876
Greenwich, CT would have the largest bay scallop fishery – during this brutal
cold and stormy period.In 1876 most of
New England ports would be locked in heavy ice by December, but bay scallop
fisheries in 1878, two years later would be huge?Blue crabs were extremely scarce in 1878, but
Noank, Connecticut became New England’s lobster capital, and four decades later
only to be the site of a lobster hatchery to help replenish small lobsters for
a failed lobster fishery but was now the site of now a growing blue crab
fishery?These events are recorded in
the fishery statistics for our region.

These
species all appear to reverse – In conjunction with habitat quality either
being reduced or rebuilt by the negative or positive phases of the North
Atlantic Oscillation (NAO). The NAO is one of the most studied and recognized
climate patterns in the world.

If
you follow the negative and positive phases of the NAO, years lateryou mirror catches of fish and
shellfish. A positive NAO warm few storms certain species thrive, a negative
NAO, cold and stormy, the same could be said for other species.

This
spring could be the difference for blue crab habitat quality – another long
cool spring could mean a late Megalops set – again. This would be the second
negative NAO winter in a row for blue crabs.

In
the 1950s and 1960s two or three cold springs was often reflected in decreased
catches of blue crabs. We might be seeing the first habitat succession changes
now in a long cyclic process.These
changes could improve lobster habitat quality years from now.

The
species to watch --adult lobsters returning to western Long Island Sound better winter flounder recruitment in eastern
Connecticut and bay scallops increasing to our north.That would signal a possible habitat
reversal.The climate pattern to watch
is the NAO – a sharp negative phase coincided with a steep drop in blue crab
populations in southern New England 50 years ago. A habitat succession process
that soon favored lobsters not blue crabs; it could happen again.Reports of winter kill blue crabs would be important
after the ice leaves in a few weeks.

Every
observation is valuable as we learn more about our blue crab population.

The
Search for Megalops is part of a Project Shellfish/Finfish Student/Citizen
Monitoring Effort Supported by a 2005 grant to The Sound School from the
National Fish and Wildlife Foundation grant #2005-0191-001.

Program
reports are available upon request.

For
more information about New Haven Environmental Monitoring Initiative or for
reports please contact Susan Weber, Sound School Adult Education and Outreach
Program Coordinator at susan.weber@new-haven.k12.ct.us

The
Sound School is a Regional High School Agriculture Science and Technology
Center enrolling students from 23 participating Connecticut communities.